End ported roller pump



Jan. 28, 1964 E. E. cooK 3,119,345

END PORTED ROLLER PUMP Filed May 24, 1962 FIE. 1 z+ rr5z a INVENTOR.fez/e37- 5. Cook United States Patent Ollice 3,11%,345 Patented Jan. 28,1964 3,119,345 END PORTED RGLLER PUMP Ernest E. Cook, Anoha, Minn,assignor to l-lypro Eng?- neering, inc Minneapolis, Minn, a corporationof Minnesota Filed May 24, 1962, Ser. No. 197,318 2 tClairns. Cl.10313o) This invention relates to rotary pumps and more particularly torotary pumps of the type which employ freetloating roller elements.

It is an important object of the invention to provide a pump of theclass described which has a high capacity for its size and is efi'icicntand economical, both in manufacture and in operation.

Another object of the invention is to provide a rotor and rollerassemblage which maintains a fluid piston in connection with each of therollers so as to increase the eificiency of fluid flow under high speedand to reduce the noise and wear within the pump.

A still further object or" the invention is to provide an end portingarrangement such that fluid fiow is established in parallel relationboth above and below the rollers with each roller maintained againstendwise displacement.

These and other objects and advantages of this invention will more fullyappear from the following description, made in connection with theaccompanying drawing, wherein like reference characters refer to thesame or similar parts throughout the several views and in which:

FIGURE 1 is an end elevation looking in the direction of the inlet andoutlet;

FlGURE 2 is a vertical section of the pump taken on the line 22 ofFIGURE 1;

FIGURE 3 is another section taken on the line 33 of FIGURE 2 and lookingin the direction of the arrows;

FIGURE 4 is a view or" the inside of the end plate showing the ports andinlet and outlet, the view being taken on the line 44 of EEGURE 2; and

FIGURE 5 is a fragmentary view of the porting end of the pump inenlarged horizontal section taken on the line 55 of FIGURE 1.

With continued reference to the drawing, the invention generallycomprises a housing Ill and a rotor assemblage ll journaled therein. Theelements are so arranged that the pump is driven from the right as shownin FIGURE 2 and all of the fluid how is substantially axial to the rotorand occurs through porting disclosed to the left as shown in the sameview.

The housing 19 may be conveniently formed in two main portions such thata cup-shaped body 12 constitutes one part and the ported end plate 13constitutes the other. A cylindrical pumping chamber l lis defined byan'inner circumferential wall 15 and a circular end wall 16 as bestshown in FXGURES 2 and 3. The cup-shaped body 12 is further providedwith a boss 17 having a cavity 18 formed therein. A shaft opening 19 isformed through end wall 16 and centered with respect to the cavity 13. Asealed roller bearing assemblage 26 is fitted in cavity 1% so as to lieagainst a shouldered portion 21 of the cavity and a shaft seal 22 alsolies within the cavity 18 in inwardly spaced relation to the bearingassembly 20. A weep hole extends vertically downward at 23 so as to passthrough the boss 17 and permit fluid which may have passed the seal todrip outwardly from between the bearing assembly 25 and shaft seal 22.In the end wall 16 is formed a shallow cavity 24 as shown in FIGURE 3and this cavity communicates with a small passageway 25 which leads tothe space as which exists between the end wall 16 and the shaft seal22;. Thus, any fluid which escapes through the shaft opening 1% and intothe space 26 will be subjected to a reduced pressure resulting from thecommunication through passageway 25 with the suction or inlet side ofthe pump.

It will be observed from FIGURES 2 and 3 that, while the cylindricalpumping chamber is circular in configuration, the shaft opening 19 issomewhat above the true center axis of the pumping chamber.

The outer edge of the cup-shaped body 12 terminates in a planar flange2'7 having a plurality of tapped openings 23 formed therein. The otherprincipal portion of the housing It) is the end plate 13 which has aflange area 29 lying in a single plane and adapted to interiit over theplanar area 27 of the cup-shaped body 12. The end plate 13 is alsoprovided with openings 3t? which register with the tapped openings 28 ofthe cup-shaped body and may be provided with cap screws 31 or studs 32with set nuts 33 and retaining nuts 34 as shown in FIGURE 2, the studassemblages serving both to maintain the end plate 13 fastened in thehousing and to provide means for convenient mounting of the entire pumpto an external mounting structure (not shown). An end wall 35 is alsoformed on end plate 13 and this end wall may be slightly raised, exceptfor the marginal relief areas 36, from the plane of the flange 29.Marginal relief areas 36 permit complete operability of the rollers outto the circumference l5, and guard against entrapment of any portion ofthe pumped fluid. End wall 35 lies in spaced parallel relation to theend wall 16 and defines the width of the cylindrical pumping chamberpreviously referred to. A partially recessed ring 37 is disposed betweenthe juncture of end wall 35 and flange 29 and serves to seal thejuncture between the end plate and the cup-shaped body.

Formed in the end plate 13 is an inlet port 38 and an outlet port 39 asshown in FIGURE 5. The inlet port cavity 38 is formed :arcuately aboutthe axis of shaft opening 49 shown in 'FlGURE 4. Shaft opening 41 is inalignment the shaft opening ll? and also lies vertically above the trueaxial center of the cylinder pumping chamber as defined bycircumferential walls 15 when the end plate is in place. Inlet port 38communicates with the inlet 41 which in turn is formed in boss &2 as anintegral fixture of the pump. An elongated rib 43 runs alrouately forthe length of the inlet port 38 and lies in the same plane as theremainder of the end wall 35'.

Diametrically opposite from the inlet port 33 is the outlet port 39'which in turn communicates with outlet 44 threadedly formed in boss 45which, like boss 42, is integral with the end plate 13 and provides afitting connection. Ari elongated rib 4-6 extends arouately for thelength of the outlet port 39, like its counterpart rib 43, lies in thesame plane with the remainder of the end wall 35 as shown in FIGURES 4and 5.

Shaft opening 45b in the end plate 13 communicates with shoulderedcavity 47 which in turn retains the hearing assemblage 48 and the shaftseal 49 as best seen in FIGURE 5. A passageway 5d passes through the endwall 55 of end plate 13 and communicates with the space 51 which liesbetween the seal ring 49 and the end plate 13 as shown in FIGURE 5. Itwill be noted that passageway Sll also communicates with the suction orinlet side of the pump so that a reduced pressure is exerted on thespace 51, thereby removing any liquid which may lie inwardly of the seal49. Referring to FIGURE 2, it will be seen that a drainage or weep hole52 is provided through the end plate so as to extend downwardly from thespace 53 which occurs between bearing assemblage 48 and the shaft seal49.

The pump rotor 11 has a rotor body 54- of circular shape which in turnis mounted upon shaft 55 and secured thereto by such means as set screw56. Shaft 55 is journaled through the bearing assemblages Zil and 48 aswell as through the housing openings and seals previously described. Theshaft extends outwardly of the pump housing in an extension 57 which maybe coupled to a power source of suitable character. The circumference 58of the rotor 54 as previously noted is concentric with the axis of shaft55 and is eccentric with respect to the cylindrical inner surface 15 ofthe pumping chamber. The upper portion of the circumferential surface 58is almost in contact with the wall 15 as shown in FIGURE 3 while thelower portion is substantially spaced therefrom and defines positivepumping spaces, the volume of which changes as the rotor body 54rotates.

Formed across the rotor body 54 and extending radially inward are aplurality of roller receiving slots 59 as shown in FIGURE 3. Each ofthese slots has a leading face 60 and a trailing face 61 which confrontone another in spaced parallel relation. A cylindrical roller element 62lies within each of the slots 59 and is movable inwardly and outwardlywithin each slot. An important feature of the invention resides in thedepth of the slot which provides a substantial clearance 63 inwardly ofthe roller 62, even when it has been depressed radially to its fullestextent as exhibited by the uppermost roller in FIGURE 3. When each ofthe rollers 62 reaches the lowermost position, the space 63 is increasedand the roller actually extends somewhat beyond the outer circumference58 of the rotor body 54.

In the use and operation of the invention, the rotor body 54- liessliding contact with the end walls 35 and 16 as shown in FIGURE 2 andthe shaft 55 together with the rotor body 54 rotates in a clockwisedirection as viewed in FIGURE 3. The rollers 62 are thrown outwardly bycentrifugal force so as to ride against the inner circumferentialsurface 15 and also to slide against the trailsing surface 61 of each ofthe slots 59. The clearance between each roller 62 and the leadingsurface 60 is very small to prevent passage of fluid from the area 63beneath the roller. As each roller moves with the rotor 54, it maintainscontact with the circumferential surface 15 at the inside of thecup-shaped housing body and begins to move outwardly in its slot 59 asthe outer circumference of the rotor leaves the inner housing surface.The rollers 62 also lightly contact the end wall surfaces 16 and 35 andas the rollers continue over the inlet port 38, the expanding space 63causes fluid to be pulled in from inlet 41 to occupy the space beneatheach roller. Also, it will be noted that the space outwardly of therotor body and between consecutive rollers begins to increase and likewise exerts a pulling force on the fluids in the inlet port 38. Sincethe rib 43 is arcua-te and continuous for the length of the inlet port38, each roller 62 is maintained in proper lateral position as it passesthereover.

As previously noted, the small passageway 50 connects with the inletport and exerts a suction force upon the space between the end wall 35and the shaft seal 4-9. Any liquid trapped in the space is thus pulledback into the rotor and is intermixed with the pumped fluid. The inletport 38 terminates short of the maximum throw of each roller and hencethere is no further intake of fluid from the inlet 41 through portHowever, as the roller 62 continues in its travel in a clockwisedirection as viewed in FIGURE 3, the space between the rotor body 64 andthe inner circumferential surface 15 begins to diminish. Shortlythereafter it reaches the lower end of the outlet port 39 and again theroller 62 rides upon a rib member 46 to prevent endwise displacement.The liquid which was pulled into the slot 59- in the space 63 is nowcaused to move laterally outward and be discharged through the outletport 39. In a similar manner, the liquid forwardly of the roller 62 iscaused to be squeezed into the outlet port 39. The ports are thussel-f-valving in character and the consecutive increasing anddiminishing volumes associated with each roller cause a continuous flowof liquid into the inlet 40- and out of the outlet 44. Since the smallpassageway 25 also lies at the inlet side of the pump, the previouslynoted evacuating effect will be exerted on fluid which may becomeentrapped between the end wall it and shaft seal 26'.

Each of the slot elements 5) is so dimensioned as to create a reservoiror fluid piston which is constantly maintained in the space d3. Thisreservoir effectively permits a simultaneous movement of the rollers atboth ends outwardly in contact with the inner circumferential surface 15despite the fact that the fluid flow is endwise of the rotor.

The average distance travelled by incoming fluid and outgoing fluid isless than when no reservoir is employed. The reservoir space 63 thuseifectively decreases the average velocity of the pumped fluid andundesirable forces which tend to move the rollers out of their parallelrelation with the rotor axis are minimized. It will also be noted thatliquid is pulled in from the inlet 41 directly into the rotor withoutnegotiating change of direction and flow. Similarly, the fluid is pumpedin a reverse direction without change of direction directly into theoutlet 44.

The noted arrangement makes it possible for both the inlet and outlet tobe located at one side of the rotor and to be aligned in close parallelrelation with the rotor shaft and with each other.

It will, of course, be understood that various changes may be made inthe form, details, arrangements and pro portions of the parts withoutdeparting from the scope of this invention as set forth in the appendedclaims.

What is claimed is:

1. A fluid pump comprising:

(a) a housing having a cylindrical pumping chamber therein,

(15) said pumping chamber being defined by an inner circumferential walland a pair of spaced circular end walls;

(c) a rotor rotatably mounted within said pumping chamber and having itsaxis in offset parallel relation to that of said pumping chamber andhaving a width such as to extend from one of said circular end walls tothe other,

,(d) said rotor having a plurality of roller receiving slots having aleading face and a trailing face confronting one another in spacedparallel relation formed into and extending throughout the entire widthof said rotor;

(e) a roller disposed for free rotation in each of said slots extendingfrom one of said circular end walls to the other and having a diametersubstantially equal to the distance between said parallel leading andtrailing faces so that there is an eflective sealing clearance with saidfaces at all times;

(f) the radial depth of said slots being substantially greater than thediameter of said rollers so that a substantial clearance forming aneffective fluid reservoir will continually be maintained inwardly ofeach roller even when each of said rollers is in its inwardrnostposition;

(g) a generally arcuate inlet port formed through one of said circularend walls, and

(h) a generally arcuate outlet port formed through the same circular endwall, said arcuate inlet and outlet ports being diametrically opposedand positioned so as to communicate with said slots during rotation ofsaid rotor.

2. A fluid pump comprising:

(a) a housing having a cylindrical pumping chamber therein,

(b) said pumping chamber being defined by an inner circumferential walland a pair of spaced circular end walls;

(0) a rotor rotatably mounted within said pumping chamber and having itsaxis in offset parallel relation to that of said pumping chamber andhaving a width such as to extend from one of said circular end walls tothe other,

(d) said rotor having a plurality of roller receiving slots having a.leading face and a trailing face confronting one another in spacedparallel relation formed into and extending throughout the entire widthof said rotor; (e) a roller disposed for :free rotation in each of saidslots extending from one of said circular end walls to the other andhaving a diameter substantially equal to the distance between saidparallel leading and trailing faces so that there is an effectivesealing clearance With said faces at all times;

(1) the radial depth of said slots being substantially greater than thediameter of said rollers so that a substantial clearance forming aneffective fluid reservoir will continually be maintained inwardly ofeach roller even when each of said rollers is in its inwardmostposition;

(g) a generally arcuate inlet port formed through one of said circularend walls;

(It) a generally arcuate outlet port formed through the same circularend wall, said arcuate inlet and outlet ports being diametricallyopposed and positioned so as to communicate with said slots duringrotation of said rotor, and

(i) a longitudinal rib dividing each of said inlet and outlet ports intotwo portions and lying in the same plane of said one circular end wall,said inlet and outlet ports and their respective ribs being positionedso as to communicate with said slots and to provide restraint againstlateral displacement of said rollers.

References Cited in the file of this patent UNITED STATES PATENTS1,466,904 Jackson Sept. 4, @1923 1,738,345 Barlow Dec. 3, 1929 1,749,121Barlow Mar. 4, 1930 23 92029 Davis Ian. 1, 1946 2,393,223 Rosen Jan. 15,1946 2,405,061 Shaw July 1946 2,525,6 19 Roth Oct. 10, 1950 2,612,110Delegard Sept. 30, 1952 2,660,123 Vlachos Nov. 24, 1953 2,7321126 SmithJan. 24, 1956 3,072,067 Beller Jan. 8, 196 2 FOREIGN PATENTS 856,687Great Britain Dec. 21, 1960

1. A FLUID PUMP COMPRISING: (A) A HOUSING HAVING A CYLINDRICAL PUMPINGCHAMBER THEREIN, (B) SAID PUMPING CHAMBER BEING DEFINED BY AN INNERCIRCUMFERENTIAL WALL AND A PAIR OF SPEACED CIRCULAR END WALLS; (C) AROTOR ROTATABLY MOUNTED WITHIN SAID PUMPING CHAMBER AND HAVING ITS AXISIN OFFSET PARALLEL RELATION TO THAT OF SAID PUMPING CHAMBER AND HAVING AWIDTH SUCH AS TO EXTEND FROM ONE OF SAID CIRCULAR END WALLS TO THEOTHER, (D) SAID ROTOR HAVING A PLURALITY OF ROLLER RECEIVING SLOTSHAVING A LEADING FACE AND A TRAILING FACE CONFRONTING ONE ANOTHER INSPACED PARALLEL RELATION FORMED INTO AND EXTENDING THROUGHOUT THE ENTIREWIDTH OF SAID ROTOR; (E) A ROLLER DISPOSED FOR FREE ROTATION IN EACH OFSAID SLOTS EXTENDING FROM ONE OF SAID CIRCULAR END WALLS TO THE OTHERAND HAVING A DIAMETER SUBSTANTIALLY EQUAL TO THE DISTANCE BETWEEN SAIDPARALLEL LEADING AND TRAILING FACES SO THAT THERE IS AN EFFECTIVESEALING CLEARANCE WITH SAID FACES AT ALL TIMES; (F) THE RADIAL DEPTH OFSAID SLOTS BEING SUBSTANTIALLY GREATER THAN THE DIAMETER OF SAID ROLLERSSO THAT A SUBSTANTIAL CLEARANCE FORMING AN EFFECTIVE FLUID RESERVOIRWILL CONTINUALLY BE MAINTAINED INWARDLY OF EACH ROLLER EVEN WHEN EACH OFSAID ROLLERS IS IN ITS INWARDMOST POSITION; (G) A GENERALLY ARCUATEINLET PORT FORMED THROUGH ONE OF SAID CIRCULAR END WALLS, AND (H) AGENERALLY ARCUATE OUTLET PORT FORMED THROUGH THE SAME CIRCULAR END WALL,SAID ARCUATE INLET AND OUTLET PORTS BEING DIAMETRICALLY OPPOSED ANDPOSITIONED SO AS TO COMMUNICATE WITH SAID SLOTS DURING ROTATION OF SAIDROTOR.